Pulverizing apparatus



Sept. 10, 1935. F, H. DANN-:Ls 2,013,800

PULVERIZING APPARATUS Filed June 26, 1931 2 Sheets-Sheet 2v INVENTOR fafa H. DAN/ELS B @4M-) /5 ATTORNEY Patented Sept. 10, 1935 UNITED STATES PATENT OFFICE PULVERIZING APPARATUS Application June 26, 1.931, Serial No. 546,962

2 claims. (ci. 83-11) This invention relates to pulverizing apparatus, and more particularly to machines of the beater type which pulverize material finely by the action of impact or attrition members mounted upon a rotor and arranged to be revolved at a high velocity.

In constructing machines of this type for greater capacities, it has heretofore been the practice to enlarge the diameter of the rotor. At

l0 -the same time it has been necessary to reduce the speed at which the rotor is driven, in order to avoid dangerous and excessive linear velocities f adjacent to its periphery. If the driving motoris directly connected .to the pulverizer shaft by means of a coupling, as is frequently the case, this motor must likewise be selected for thelower rotational speed and hence will be more bulky and expensive for a given horsepower than a higher speed motor. Moreover, it is found that if the diameter of a pulverizer of this type is increased, a

' point is eventually reached where the efficiency begins to decrease, although the eifciency of the Idriving motor is usually greater the higher its rated horsepower.

It is accordingly one object of the invention to provide a pulverizing apparatus of large capacity which is so arranged that it may be operated at a comparatively high rotational speed, and which will reduce material to a desired degree of fineness with a minimum consumption of power.

It is a further object of the invention to provide a pulverizing apparatus which is of compact construction and which will occupy the minimum of space for a given pulverizing capacity.

It is a further object of the invention to provide a pulverizing apparatus which is so arranged that all parts subject to wear are readily accessible for renewal.

It is a further object to provide a pulverizing apparatus which is simple and inexpensive to manufacture and install.

With these and other objects in view, as will be apparent to those skilled in the art, my invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of my invention, and in which like reference numerals indicate like parts,

Fig. `1 is a section througha pulverizing apparatus, the section being taken substantially on the line I-I of Fig. 2;

Fig. 2 is a section on the line 2 2 of Fig. 1;

Fig. 3 is a section on the line 3 3 of Fig. 1:

55 Fig. 4 is a section on the line 4-4 of Fig. 1;

Fig. 5 is an enlarged sectional view showing the separable joint in the pulverizing chamber wall; and

Fig. 6 is a detail of a stationary peg. v

The embodiment of the invention illustrated in 4I5 the drawings comprises a casing III shaped to provide a pulverizing chamber I I having a peripheral inlet opening I2 for the coarse materialv and two central outlet openings I4 for the pulverized material. As shown particularly in Fig. 2, the inlet 10 I2 leads downwardly into the pulverizing chamber at one side of the vertical axial plane, and extends throughout substantially one quarter of the circumference of the chamber. In an axial direction, the inlet opening is of the same width as the 15 pulverizing chamber. As best shown in Fig. l, the outlet openings I4 are located directly opposite each other in the side walls of the chamber.

Within the chamber Il I provide a rotor I5, which is illustrated as a vertical disk arranged to 20 rotate about a horizontal axis. This disk I5 is mounted on a horizontal shaft I6 which extends through the outlet openings I4 and is rotatably supported in bearings I8. A half coupling I9 is shown on one end of the shaft for convenience in 25 connecting a driving motor thereto. Pulverizing elements 2| are mounted on the disk I5. The members 2| illustrated are of the general type disclosed in the patent to Craig, No. 1,714,080, and

.are shaped as pegs formed integral with seg- 30 mental wear plates 22. The plates 22 are fastened to the sides of the disk I5 adjacent to the periphery thereof by means of bolts 23. With this construction, the pegs 2l form spaced annular rows on opposite sides of the rotor disk. These pegs 2| 35 preferably extend only part Way to the side Walls of the pulveriz'mg chamber, so that a free space is provided between these parts through which material of sufficient fineness may flow towards the centrally located outlets I4. 40

It will be clear that in passing through the pulverizing chamber I I the material must travel against the centrifugal force set up by the revolving pegs 2I. In order to transport the material through the machine against this force, I utilize 5 powerful air currents which may be produced in various ways but which are preferably set up by suction fans connected to the outlet openings I4. In the preferred embodiment illustrated, the casing I0 is extended to provide a fan chamber 25 at ,each side of the central pulverizing chamber II.

and a fan 26 is mounted on the shaft I6 and ar ranged to rotate therewith. As shown in Fig. 3, the peripheral wall of each fan chamber 25 is shaped as a volute or scroll leading to a discharge .pegs 2|, it is found that particles occasionally reach the outlets I4 which are coarser than is desirable. In order to prevent the escape of such coarse particles into'the fan chamber, I provide rejector blades 30 which revolve adjacentto the outlets. These blades 30 are U-shaped in cross section and extend outwardly in substantially radial directions from the shaft I 6. In the embodiment illustrated I have shown four rejector blades adjacent to each outlet, and these serve to scoop coarse particles from the issuing cloud of material and hurl them back into the pulverizing chamber. Each set of rejector blades 30 revolves adjacent to a rejector ring 3| which surrounds the shaft. These rings 3| define the outlet openings I4 leading fromthe pulverizing chamber to the fan chambers.

In addition to the revolving pegs 2|, I preferably provide stationary pegs 33 which assist in the pulverization of the material. `The pegs 33 are shown arranged in annular rows projecting from both side walls of the pulverizing chamber and extending toward the rotor. these stationary pegs are shown at each side of the rotor, and they intert with the revolving pegsas particularly illustrated in Fig. 1. Each peg is preferably formed with a thin flanged ferrule 34 (Fig. 6) of pressed steel or similar material, as disclosed in the patent to Riley No. 1,576,472. 'I'hese pegs are supported by two flat annular cheek plates 35, each of which has circular openings therein through which the pegs are inserted. Each plate 35 is formed of two sections held together byvstraps 38 (Fig. 2) for convenience in assembly.

In order to protect the peripheral portion of the casing from wear, I provide a number of anged linerl plates 38 and 39 which are bolted to the side walls of the pulverizing chamber. 'I'hese Plates extend toward each other and are locatedA -in the direct path of material hurled outwardly by the revolving pegs 2|. The plates 38 located to the right of the vertical axial plane in Fig. 2 have inwardly extending flanges, while the plates 39 located in the lower left portion of Fig. 2 and beneath the inlet I2 have outwardly extending flanges. The casing wall adjacent to these plates 39 is vertical and provided with a door 40 through which access may behad to the plates and their fastening bolts. Below the horizontal axial plane these wear plates are concentric with the rotor, but the plates inthe upper right portion of Fig. 2 are arranged on a spiral which approaches the axis in thedirection of rotation, the end of the plate directly above the rotor axis being spaced thereiromthe greatest distance. This construction is of value in obtaining uniform .distribution of the incoming material about the rotor periphery.

Referring now to Figs. 2 and 3, it will be seen that the casing I0 is divided vby three axial planes into three separate sections in order to facilitate manufacture and assembly. These sections are formed with cooperating iianges which may be bolted together. The rst andlowest section 42 extends throughout an angle oi' 135 degrees measured from the horizontal axial plane. This section forms the support for the other two, and also .carries the discharge nozzles-21, which at instal'- Two rows of lation are connected by pipes with other apparatus. 'Ihe second section 43, which includes the feed inlet opening I2, is mounted upon the lower section 42 and extends throughout an angle of degrees measured between the horizontal and 5 vertical axial planes. At assembly the section 43 is connected to the other apparatus which supplies the coarse material to be pulverized, and it is intended that this portion of the casing should remain permanently in place. The third section 10 44 of the casing is fastened to the other two and extends throughout an angle of degrees measured from the vertical axial plane. This section is so arranged that it can be readily removed to give access to the interior of the casing when it 15 is necessary to renew any of the various parts.

In order that the section 44 of the casing may be removed without any interference on the part of the stationary pegs 33, these pegs are mounted on the side walls of the pulverizing chamber II 20 -turbing the shaft. 'I'he cheek plates 35 are mounted on the rejector rings, and may be rotated thereon by hand to bring the pegs 33 successively'into a convenient position for replace- 35 ment.

In the portions 42 and 43 of the casing, the flanges of the pegs 33 are clamped between the cheek plates 35 and the diaphragms 46 by means of cap screws 41, which are readily accessible for 40 turning by a socket wrench when the section 44 of the casing is removed. 'I'he pegs 33 adjacent to the section 44 of the casing are held in place by clamping their flanges between the plates 35 and two backing plates 48 by means of cap screws 45 50. The backing plates are each shaped as a circular ring sector having an'angle of substantially 135 degrees. A tongue 5I (Fig. 5) is provided along the upper edge of each backing plate,l and ing plates, thus preventing leakage and render- 55 I ing' the side walls of the pulverizing chamber rigid at assembly.

The operation of the invention will now be apparent fromvthe above disclosure. T he discharge nozzles 21 are connected by piping to suitable 50 apparatus for utilization or storage of the pulverized material, and the inlet opening I2 is supplied with the coarse material at a controlled rate. In case the material to be pulverized is coal, it is desirable that it first be crushed to a 65 small and uniform size in a suitable hammer mill and all tramp metal removed before it enters the inlet I2. The shaft I 6 is rotated at a high speed by a suitable source of power, and the fans 26 produce powerful air currents which flow in,70

ticles remain in the pulverizing chamber and are reduced to a powder by the action of the rapidly revolving pegs 2| and the stationary pegs 33. Any coarse particles which chance tol approach the outlet openings I4 are scooped out of the issuing stream by the rejector blades 30 and hurled back into the pulverizing zone.

The apparatus is of simple construction and inexpensive to manufacture. The casing can be readily fabricated of steel plates Welded together. All parts which are subjected to wear can be easily replaced by rst removing the casing section 44, and this can be done without disturbing the inlet or discharge connections. Since the rotor is of symmetrical construction.. there is no tendency for centrifugal force to cause bending stresses therein, nor is there any unbalanced arrangement which could produce an axial thrust on the driving shaft. The machine may be of large capacity without necessitating a large rotor diameter and it may therefore be operated ata high speed safely, thus permitting the use of an eiiicient and inexpensive driving motor. tire construction is very compact and requires a minimum of oor space.

-Having 'thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A pulverizing apparatus comprising a casing shaped to provide a pulverizing chamber and a fan chamber at one side of the pulverizing cham- The enber, the pulverizing chamber being connected to the. fan chamber by a centrally located passage, a horizontal rotatable shaft extending through the casing, a rotor mounted on the shaft within the pulverizing chamber, impact members on the 5 rotor, and a fan mounted on the shaft within the fan chamber., the fan chamber having a peripheral wall shaped as a scroll leading to a discharge connection adjacent the up-running portion of the fan, the pulverizing chamber having a periph- 10 eral inlet opening adjacent the up-running portion of the rotor, and the casing-having a removable section located adjacent the down-running portions of the fan and rotor to allow access to the interior of the casing. 1 2. A pulverizing apparatus comprising a casing shaped to provide a pulverizing chamber, a rotor `mounted within the pulverizing chamber and arranged to rotate about a horizontal axis, pulverizing elements on the rotor, the pulverizing cham- 20 ber having. a peripheral inlet located adjacent the up-running side of the rotor and an outlet located adjacent the axis of the rotor, the peripheral wall of the chamber being shaped to form a spiral starting at the inlet and gradually approaching 25 the rotor in the direction of rotation thereof, and means to pass a current of air through the casing to carry the pulverized material through the outlet.

lFRED H. Damme. 3 

